My take on it is this. AI, and specifically Machine Learning, will be accumulating a fantastic amount of information experience in the years to come. By that I mean that ML will use Big Data, particularly from the Internet of Things (Internet connecting most objects and mechanisms to each other). The skills it accumulates will start as an infant, knowing only pieces of various skills, but it never forgets. So AI will be a big part of every facet of our lives. Trivial and repetitive tasks in advanced countries will be largely done by AI-enhanced mechanisms. At present AI can't replace humans in creative endeavors. But, contrary to the opinions of many, it will be a big part of that as well. Another thing is that innovation is usually based on new applications of existing knowledge. AI will make that application easier. Humans will continue to raise the bar, as it were, to try more and more ambitious efforts and build on what AI makes possible.
The end result of all this will be that humans will be doing more and more complicated things using AI as building blocks and tools. Humans will not be doing dangerous things as much. They will be doing different things that AI won't.
So no, AI won't make up the majority of the workforce. The workforce will be about the same size and composition as today. However, AI will be doing a lot of the things that humans used to do. Humans are far more flexible in that regard than they give themselves credit for.